It depends on just what he meant by "Flying thru Clouds". It could be literally flying through one or more Clouds, -Or,-It could be similar as when one says that they were walking thru "the Weeds or Bushes". This latter in the Meaning of one's *Passing* Thru, and By them, -Not literally walking right through them.

Of course there *could possibly* be other FAA issues there, -in either case.